2007/09/28 by Sébastien Maret, Edwin A. Bergin, Charles J. Lada · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/524014
12 pages, 3 figures, to appear in the Astrophysical Journal Letters
arxiv created 2007/09/28 · arxiv updated 2009/12/01
We present observations of 13CO, C18O, HCO+, H13CO+, DCO+ and N2H+ line emission towards the Barnard 68 starless core. The line profiles are interpreted using a chemical network coupled with a radiative transfer code in order to reconstruct the radial velocity profile of the core. Our observations and modeling indicate the presence of complex radial motions, with the inward motions in the outer layers of the core but outward motions in the inner part, suggesting radial oscillations. The presence of such oscillation would imply that B68 is relatively old, typically one order of magnitude older than the age inferred from its chemical evolution and statistical core lifetimes. Our study demonstrates that chemistry can be used as a tool to constrain the radial velocity profiles of starless cores.